*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: consolas;
}

body{
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: #000;
}

a{
    position: relative;
    width: 160px;
    height: 50px;
    line-height: 48px;
    background: #000;
    text-transform: uppercase;
    font-size: 20px;
    letter-spacing: 4px;
    text-decoration: none;
    -webkit-box-reflect: below 1px linear-gradient(transparent, #0004);
}

a::before{
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, #fb0094, #00f,#0f0,#ff0,#f00,#fb0094, #00f,#0f0,#ff0,#f00);
    background-size: 400%;
    opacity: 0;
    translation: .5s;
    animation: animate 20s linear infinite;
}

a::after{
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, #fb0094, #00f,#0f0,#ff0,#f00,#fb0094, #00f,#0f0,#ff0,#f00);
    background-size: 400%;
    opacity: 0;
    filter: blur(20px);
    translation: .5s;
    animation: animate 20s linear infinite;
}


a:hover::before,
a:hover::after{
    opacity: 1;
}

@keyframes animate{
    0%{
        background-position: 0 0;
    }

    50%{
        background-position: 300% 0;
    }

    100%{
        background-position: 0 0;
    }
}

a span{
    position: absolute;
    display: block;
    top: 1px;
    left: 1px;
    right: 1px;
    bottom: 1px;
    text-align: center;
    background: #0c0c0c;
    color: rgba(255,255,255,0.2);
    translation: .5s;
    z-index: 1;
}

a:hover span{
    color: rgba(255,255,255,1);
}

a span::before{
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 50%;
    background: rgba(255,255,255,0.1);
}

